The biosynthesis of a bacterial polysaccharide—the surface O-antigen Salmonella newington —differs in several respects from the more classical example glycogen synthesis. Sugars are not transferred directly to antigen sugar nucleotide precursors but first into lipid-linked oligosaccharides. Growth polysaccharide chain then occurs by assembly these at reducing end polymer rather than its nonreducing as glycogen. This method assembly, which nascent chains next subunit, is analogous growth...

We introduce an intuitive particle-based model of time-symmetric quantum physics that gives a concrete description what goes on in the time between projective measurements system. The time-symmetry this means we ...Physical interpretations formulation mechanics, due to Aharonov, Bergmann, and Lebowitz are discussed terms weak values. most direct, yet somewhat naive, interpretation uses ...

We have analyzed the functions encoded by bgl operon in Escherichia coli K-12. Based on ability of cloned regions to complement a series Bgl- point mutations, we show that three structural genes, bglC, bglS, and bglB, are located downstream regulatory locus bglR order indicated. Using bgl-lacZ transcriptional fusion, bglC bglS involved regulating expression. The presence gene trans is absolutely required for expression which constitutive when only present. When genes both present cell,...

The flow of water beneath the Antarctic Ice Sheet has recently been shown to involve drainage from and exchange between subglacial lakes, with routing over distances >100km. As is known be important ice‐sheet dynamics, changes basal may yield an response. Here we show that directions hydrological flowpaths are highly sensitive surface topography at certain sites in Antarctica. Surface elevation changes, 5 15 m, found sufficient produce significant flowpaths, which affect potential routes...

The refreezing of meltwater is known to be a critical factor when assessing the mass balance state glaciers in high Arctic. Several different models this process are widely used numerical glacier simulations but, as yet, no attempt has been made compare these approaches or assess their relative performance against field measurements. Such likely include implicit calibrations which may prove invalid under conditions from those for they were constructed. We test selection six algorithms taken...

Amber mutants with defects in the dnaA gene of Escherichia coli K-12 were isolated after localized mutagenesis tna-dnaA region chromosome. We 36 defective initiation deoxyribonucleic acid replication as determined by their dependence upon integrative suppression a P2 sig5 prophage. Three shown to contain amber mutations through use temperature-sensitive suppressor. These mutations, which mapped between gyrB and tna, characterized genetically biochemically dnaA.

The product of the dnaA gene is essential for initiation chromosomal DNA replication in Escherichia coli K-12. A cold-sensitive mutation, dnaA(Cs), was originally isolated as a putative intragenic suppressor temperature sensitivity dnaA46 mutant (G. Kellenberger-Gujer, A. J. Podhajska, and L. Caro, Mol. Gen. Genet. 162:9-16, 1978). cold dnaA(Cs) attributed to loss control resulting overinitiation replication. We cloned sequenced from showed that it contains three point mutations addition...

Polysaccharide synthesis is discussed from the point of view sources biological information that determine structures and control rates complex polysaccharides. It concluded three types contribute in important different ways, namely enzyme specificity, primer substances, structure cytoplasmic membrane. Each these factors a general way with examples its contribution to organization specific

The process of sequential bending has many applications, but the most common is for developing cylindrical shapes from plate. objective this work to develop a model use in simulation manufacturing such objects, provide design sensitivity information, and explore potential improved control. modeled here as series overlapping two-dimensional three-point bends, where overlap includes plastic zone previous bends. This deformed both non-flat initial geometry next bend locally strain-hardened...

Localized mutagenes of Salmonella typhimurium followed by a [3H]uridine enrichment procedure yielded temperature-sensitive strain with mutation in the rpo region chromosome. Ribonucleic acid (RNA) polymerase (EC 2.7.7.6; nucleoside triphosphate: RNA nucleotidyltransferase) purified from this mutant was considerably less active at nonpermissive temperature than wild-type enzyme. Furthermore, enzyme mutant, unlike previously isolated mutants, as thermostable when preincubated 50 degrees C....

The abilities of three Escherichia coli strains with thermosensitive dnaG alleles to maintain plasmids pSC101 or pBR322 an RP4 derivative were studied at elevated growth temperatures. Under these conditions, segregated from cells a greater extent than did pBR322. No segregation the primase-encoding was observed.

Instruction sets, from families like x86 and ARM, are at the center of many ambitious formal-methods projects. Many verification, synthesis, programming, debugging tools rely on formal semantics instruction but different can use in rather ways. The best-known work applying single across diverse relies domain-specific languages Sail, where language its translation specialized to realm sets. In context open RISC-V instruction-set family, we decided explore a approach, with written carefully...